Process of making tartaric acids or their compounds.



M. VAYGOUNY. PROCESS OF MAKING TARTARIC ACIDS 0R THEIR COMPOUNDS. APPLiCATION FILED JULY 21. 1910.

1,181,555. Patented May 2 1916 1X? Wwoaao I W 5 vwa vL-foz f y 35% 11M Gwen W134 AT TENT @FFIQE.

moosnnen vayeomwr, or BERKELEY, (ammonium, ASSIGNOR r0 ROYAL one p PO com any, a corveonarron or new JERSEY.

PROCESS MAKING TARTARIC ACIDS 0R THEIR mamas.

Specification of Letters Patent.

Patented-May 2, 19116).

Application filed July 21,1910. Serial No. 573,057.

To all whom it may concern Be it known that I, MoosHEeH VAY- GOUNY, a citizen of the United States,*residing at Berkeley, county of Alameda, and State of California, have invented a new and useful Process of Making Tartaric Acids or Their Compounds, of which the following is a specification.

This invention. relates to a process of making tartaric acids or their compounds from glyoxylic acid orits compounds and has as its object the making of tartaric acids or their compounds in a more economical. and eflicient manner than heretofore.

Myprocess relates to the reduction of glyogiylates under the influence of certain agents and under certain conditions where'- by two glyoxylic molecules are caused -to take up a one molecule of hydrogen, thereby resulting in tartaric acids or tartrates, as the case may be.

I shall hereinafter. describe such a process in connection with the manufacture of racemic and meso-tarta'ric acids, although it may as well be practised in connection with the manufacture of the other tartaric acids asfu'rther derivatives.

. In the following I describe, in connection with the accompanying drawing, a means v llustrating a way of carrying out my process electrolytically, (that is using the electrlc current asthe particular agent).

The drawing is a diagrammatic representation of-a double compartment electrolytic cell, illustrating one means of carrying out my process electrolytically. It is intended to be illustrative only, as it is obviousthat the part cular apparatus used is not an essential feature of the process.

In the drawing, A indicates a suitable container which may be of any desirable non-conducting material, such as wood.

The shape of it is immaterial. B- indicates the cathode provided with suitable perforations B, and C indicates the cathode terminal. Of course the container A could be dispensed with and the cathode itself be formed into a cathode chamber, the exterior being insulated i'nsome suitable manner and the perforations B inthis case, omitted. I have'found that the best cathodes to bring about the reduction in questionare madeof those conductive materials which possess the quality of low over-voltage, such as copper, gold, nickel, silver, iron or carbon. Of these, practice shows copper to be the most suitable in point of efficiency in operation combined with economy in installation. Other'metals than those specified will yield tartaric acids more or less efficiently, but

owing to their higher over-voltages they tend to yield further reduction products so that there is relatively" much less tartrate formed. r

1) indicates th anode and E the anode terminal. The anode should be.of some material not readily attacked under the conditions of use,'and I have found platinum in the form of a gauze netting to be every satisfactory. F indicates a suitable diaphragm of any desirable material separating the cathode chamber from the anode .chamber.

It is desirable, in carrying on the electrolytic reduction of a glyoxylate, to keep the surfatces of the cathode clean and bright and to employ clear solutions. When insoluble cathodes are used, .such as gold, carbon, etc, the glyoxylate solution may be strictly neutral, or nearly so, without affecting the brightnessof the: surfaces. However, when more easily soluble cathodes are used, such as copper cathodes, it is well to.

start the process with an electrolyte not strictlyineutral but preferably slightly alkaline, and to keep it in such condition throughout the duration of the reduction,

necessary. Under otherwise proper conditions, such a precaution will ineet 'all'requirements in this respect, as I have observedtnat in such alkaline solutions the surface of thecathode' remains bright and clean when once the process isstarted with (such as is obtained, for example, by buffing), as distinguished from mere chemical.

' the cell andzcleaned or their surfaces reno vated or brightened in any suitable way.

it in'this condition; Mechanical brightness.

It must be understood that quite apart from its usefulness in preserving the brightness of the surfaces of the cathodes, the approximate neutrality, or slight alkalinity, as the case-may be, of the solution, is of importance in the production of the tartrates.

. As an example of the practice of my process in connection with the electrolytic means disclosed, I give the following: 500 cubic centimeters of a solution containing 32 grams of potassium glyoxylate, 20 grams of potassium sulfate and 0.5 gram of potassium hydroxid, is introduced into the cathode chamber. For this quantity of solution and thistype of cell the cathode should preferably have unilateral surface of about 200 vent the yield in tartrates drop ing too heavily in favor of further reductlon products,a direct currentof about 4 amperes strength is caused to pass through the solu tion from the anode to the cathbde, the contents of the cell being cooled by any suitable means if necessary, so as to prevent the temperature of the solution from rising much above 20 to 25 centigrade'. It should not substantially exceed 40 centigrade. The distance between the anode and cathode may be about 1 to 1% inches,-in the example given, and the voltageunder such conditions may be about 5 volts. -As the current flows, the glyoxylateis reduced to tartrate almost in theoretical quantities, the hydrogen tending to be generated at 'the cathode being absorbed during most of the operation. In about two hours and a half under the conditions named, the reduction is complete, as is then evidenced by a brisk evolution of free hydrogen beginning on the cathode surfaces and the disappearance, of glyoxylate. Thesolution is now withdrawn from the cell and the excess of alkali (generally small) whichis formed in the cathode chamber by reason of electrolytic phenomena, is neutralzed witha part of the acid solution from t e anode chamber, or with another solution of a suitable acid if necessary. The resultant solution now-consists of a substantially pure solution of a mixture of'potassium sulfate, potassium tartrates ('racemic and meso- 5 now added a suitable precipitant of tartrate :such as a calcium salt,

. gether with a very small tartra'tes in about equal proportions) top 'oportion of potassium oxylate and'glycolate. To this is referably calcium sulfate. grams, that 1s, nearly the theoretical quantity) which is readily converted into calcium tartrates' and precipitated as such. There is thus formed, of course, a

7 corresponding quantity of potassium sulfate -Wh1ch remains in solution.

taric acids, which latter,,in turn, .may be evaporated to crystallization, if desired, in which case the racemic acid separates out almost completely .first, leaving meso-ta taric acid in the mother liquor.

During the process of reduction the mostsatisfactory temperature at which the solution may be maintained is about 20 centigrade, and for the satisfactory working of the process the temperature should not be allowed to rise much above 30 to 40 centigrade, nor to fall much below 10 centigrade. i

The concentration of the solution of the glyoxylate employed should be moderate, 10 to 20%having been found the most satisfactory. A solution of above 20% glyoxylate tends to be uneconomical in practice because the glyoxylate employed then tends to take part too freely in the conduction of the current, being thereby carried into the in the example given, potassium sulfate. By

so doing the potassium sulfate, being a far better conductor thanthe glyoxylate present, will diminish the number of glyoxylic ions carried into the anode compartment.

The current density on the cathode should be kept between certain limits, as, for a given rate of agitation of the solution, the current density for good yields in tartrates will be higher the more vigorous the mechanical agitation of the cathodesolution. The most satisfactory cathode density find to be about 1 to 4 amperes per square to violent stirring, as would be necessary in case much higher current densities were employed.

While I have described in the foregoing a special form of cell which may be used in decimeter of operative cathode surface for an ordinary agltation without having resort in practising my process. It is'f'urther ob vious that the character and size of the electrodes, the temperatures, the degree of concentration of the solutions employed,- the current strength and density and the manner or rate of agitation of the solutions may be varied within limits to suit the conditions of operation in commercial. practice and I do not precisely limit myself in any of these particulars.

Furthermore, while I have illustrated my process in connection with the. use of potasfer to use, the electric current is availed of' as the agent instrumental in bringing about the reduction'of the glyoxylates to the tartrates. I do not, however, limit myself to that particular agent (except in the claims specifically designating it): as there are other agents which might be used for the same purpose. The agent may be, for example,

'metallic couples introduced into the solu-- tions kept under otherwise satisfactory conditions. Suitable couples would be a copper-iron couple, a copper-gold couple, an iron-platinum couple, or many other similar couples,"the object being to cause the addition of hydrogen to the 'glyoxylic molecules under proper conditions.

Another available group of agents comprises the use of hydrogen with certain metals having such physical properties as will renderthe element hydrogen labile, ac-

tive and nascent, as it were, under the condi-' tions above described toward the glyoxylates and reduce them to tartrates, As examples of such. metals, I may mention platinum, palladium, gold, nickel, copper. etc.,

used in their spongy or colloidal states, for

instance, in the presence of free hydrogen.

I believe I am the first to provide a commercially-operative process for the production of tartrates from glyoxylates.

I claim: I 1. -A process of making tartaric acids or their compounds comprising the reduction,

. by an electric current, of a glyoxylate.

2. A process of making tartaric acids or their compounds comprising the reduction, by an electric current, of a neutral or nearly neutral solution of a glyoxylate.

3. A process of making tartaric acids or their compounds comprising the reduction,

by an electric current, of an alkali glyoXylate. I

4. A process of making tartaric acids or their compounds comprising the reduction,

by an electric current, of a neutral or nearly neutral solution of an alkali glyoxylate. 5. A process of making tartaric acids or their compounds comprising the reduction, py an electriccurrent of potassium glyoxyate.

6. A process of making tartaric acids or their compounds comprising the reduction,

by an" electric current, of a neutral or nearly neutral solution of potassium glyoxylate.

7. A process of making tartaric acids or their compounds comprising the reduction,' by an electric current, of a glyoxylate, neutralizing the resultant solution and reacting the same with a precipitant of tartaric acids.

8. A process of making tartaric acids or their compounds comprising the reduction,

by an electric current, of a neutral or nearly neutral solution of a glyoxylate, neutralizing the resultant solution and reacting the same with a precipitant of tartaric acids.

9. A process of. making tartaric acids or their compounds comprising. the reduction, by an electric current, of an alkali glyoxylate, neutralizing the resultant solution and reacting the same with -'a precipitant of tartaric acids.

10. A process of making tartaric acids or their compounds comprising the reduction, by an electric current,'of a neutral or nearly neutral solution of an. alkali glyoxylate, neutralizing the resultant solution and re- -actingthe same with .a precipitant o tartaric acids.

11. A process of making tartaric acids or their compounds comprising the reduction,

by an electric current, ofpotassium-glyoxylate, neutralizing the resultant solution and reacting the same with a precipitant of tartaric acids.

12. A process of making tartaric acidsor their compounds comprising the reduction, by an electric current, of a neutral or nearly neutral solution of potassium glyoxylate, neutralizing the resultant solution and reacting the same with a precipitant oftartaric-acids.

13. A process of making tartaric acids comprising the reduction, by an electric current, of a neutral or nearly neutral solution of .a glyoxylate, neutralizing the re sultant solution, reacting the same with a calcium salt, filtering 01f the resulting calcium tartrates and decomposing the same with an acid toliberate the tartaric acids.

14. A process of making tartaric 'acids comprising the reduction, by an electric current, of an alkali glyoxylata'neutralizing the resultant solution, reacting the same with a calcium salt, filterin off the resulting calcium tartrates and. ecomposing the same W1th an acld to liberate the tartarlc comprising the reduction, by an electric current, of potassium glyoxylate, neutralizing the resultant solution, reacting the same with a calcium salt, filtering off the resulting calciumtartrates and decomposing the same with an acid to liberate the tartaric acids.

.17. A process of making tartaric acids comprising electrolyzing a neutral or nearly neutral solution ofpotassium glyoxylate, neutralizing'the resultant solution, reacting the same with a calcium salt, filtering ofl the resulting calcium tartrates and decomposing the same with an acid to liberate the tartarlc acids.

18. Aprocess of making tartaric acids or.

their compounds comprising'the reduction of a .glyoxylate' in a solution free from organic acid other than glyoxylic acid.

1 9. A process of making tartaric acids or their compounds comprising-the reduction 1 of a neutral or nearly neutral solution of a glyoxylate.

20. A process of making tartaric acids or theirpompo'undscomprising subjecting glyoxylates in a solution free from orgamc acid other than glyoxylic to the influence of a suitable agent to cause them to unite With hydrogen simultaneously rendered available.

their compounds-comprising subjecting a neutralor nearly neutral solution of a glyoxylate to the influence of a suitable agent to cause them to unite with hydrogen simultaneously rendered available.

'22; .A process of making tartaric acids -or their compounds comprising the electrolytic reduction of a glyoxylate in. the presence of a cathode not having high over-voltage.

23. A process of making tartaric acids or their. compounds comprising the reduction of a glyoxylate in an electrolytic cell pro- .Yided with a copper cathode.

24. A process of making tartaric acids or their compounds comprising the reduction of a glyoxylate at a temperature not exceeding substantially 40 centigrade.

25. A process'of making tartaric acids or their compounds comprising the reductionof a glyoxylate by an electric current of about from 1 to i amperes current density u electrolyzing. .21. A process of maklng tartaric-aclds orper square decimeter of operative cathode surface.

26. A'process of making tartaric acids or their compounds comprising the electrolvtic reduction of a solution of a glyoxylate kept in agitation. I I

27 A process of making tartaric acids or their compounds comprising the reduction, by an electric current, of a glyoxylate in the presence of an inorganic electrolyte. 28. A process ofmaking tartaric acids or their compounds comprising the reduction,

by an electric current, of a glyoxylate in the presence of potassium sulfate.

29. A process of making tartaric acids or their compounds comprising the reduction of a glyoxylate in an electrolytic cell provided with cathodes having bright surfaces. 30. In the manufacture of tartaric acids or their compounds, a process which comprises submitting a glyoxylate to regulated or their compounds, a process which comprises submitting a non-acid solution containing'a glyoxylic compound to regul t electrolytic reduction.

, 34. In the'manufacture of tartaric acids or their compounds,- a process which comprises charging the cathode chamber of a divided cell with anon-acid solution containing a glyoxylate', charging the anode chamber with asuitable electrolyte and 35. In the manufacture of tartaric acids or their compounds, a process which comprisescharging the cathode chamber of a divided cell with a non-acid solution containing a glyoxylate, charging the anode chamber with a suitable electrolyte and electrolyzing at a low temperature.

36, In the manufacture of tartaric aclds or their compounds, a process which comprises charging the cathode chamber of a divided'cell with a non-acid solution containing a ,glyoxylate and potassium sulfate, charging the anode chamber with a suitable electrolyte and electrolyzing,

- 37. In the manufacture of tartaric acids or their compounds, a process which com prises charging the cathode chamber of a divided cell with a non-acid solution containing a glyoxylate;and a distributing conductor, charging the anode chamber with a suitable electrolyte and electrolyzing.

38. In the manufacture of tartaric acids or their compounds, a process which comspecification in the presence of tWo sub-. priseds dcharginghthe cafhcfde dchalmber of a scribing Witnesses. divi e cell wit an al a ize so ution containing glyoxylate and alkali Sm, charging MOOSHEGH VAYGOUNY' 5 the anode chamber With a suitable electro- W1tnesses:

lyte and electrolyzing. E. P. LA GAY,

In testimony whereof I have signed this LESTER H. JACOBS. 

